Bayne, who in 2011 became the youngest winner in Daytona 500 history, will still compete as scheduled at Homestead-Miami Speedway this weekend in the Nationwide and Sprint Cup Series finales. Bayne's younger sister, Sarah, also has multiple sclerosis.
"There are currently no symptoms and I'm committed to continuing to take the best care of my body as possible," Bayne said in a statement. "As for now, I want to close out the season strong this weekend at Homestead and then shift my focus on getting ready to compete for the NASCAR Nationwide Series (NNS) Championship in 2014."
Multiple sclerosis, or MS, is a chronic, inflammatory disease that's thought to cause the immune system to attack the central nervous system's brain, spinal cord and optic nerves. Symptoms can range from mild to severe and include numbness in the limbs, paralysis and loss of vision.
About 400,000 Americans have MS, with 200 new people diagnosed each week, according to the National Multiple Sclerosis Society.
The cause of the condition remains unknown. Treatments can alter the course of the disease or treat flare-ups, but there is still no cure.
Most people are diagnosed with MS between 20 and 50 years of age.
The 22-year-old Bayne was sidelined for five races in 2011 for an illness that led to hospitalization at the Mayo Clinic. Doctors ultimately called it an "inflammatory condition," and it was never made clear if it was related to an insect bite he'd suffered weeks earlier.
He underwent a spinal tap during his hospitalization, and doctors ruled out Lyme disease at the time. Bayne was initially admitted to the Mayo Clinic in 2011 for nausea, fatigue and double vision. He'd been treated weeks earlier following a race at Texas after experiencing numbness in his arm while driving, and thought the condition was related to the insect bite.
"I've never been more driven to compete," Bayne said. "My goals are the same as they've been since I started racing. I want to compete at the highest level and I want to win races and championships. I am in the best shape I've ever been in and I feel good."
Bayne was 20 when he won the Daytona 500 in 2011 driving for The Wood Brothers. It was his first Daytona 500 and briefly propelled him to national fame as the fresh new face of NASCAR.
But he was only driving a partial Cup schedule that year, and he was out of his Nationwide car eight races later when he became ill.
Bayne said he is still scheduled to drive for Roush-Fenway Racing full-time next season in the Nationwide Series, and a partial Cup schedule for The Wood Brothers. He goes into this weekend with one Nationwide Series win this year - at Iowa - and is ranked sixth in the points standings.
"We are 100 percent supportive of Trevor and his ability to compete in a race car," Roush Fenway team owner Jack Roush said. "As with all of our drivers, we look forward to standing behind Trevor and providing him with all of the tools he needs as he continues to develop in his young career."
NASCAR added in a statement, "We support Trevor and are proud of the way he's addressing his condition. We know that he's in very good hands and we're confident of his ability to continue to compete at a high level in our sport."